run.go

   1 /*
   2 goredo -- djb's redo implementation on pure Go
   3 Copyright (C) 2020-2023 Sergey Matveev <stargrave@stargrave.org>
   4
   5 This program is free software: you can redistribute it and/or modify
   6 it under the terms of the GNU General Public License as published by
   7 the Free Software Foundation, version 3 of the License.
   8
   9 This program is distributed in the hope that it will be useful,
  10 but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 GNU General Public License for more details.
  13
  14 You should have received a copy of the GNU General Public License
  15 along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16 */
  17
  18 // Targets runner
  19
  20 package main
  21
  22 import (
  23         "bufio"
  24         "crypto/rand"
  25         "encoding/hex"
  26         "errors"
  27         "flag"
  28         "fmt"
  29         "io"
  30         "io/fs"
  31         "log"
  32         "os"
  33         "os/exec"
  34         "path"
  35         "strconv"
  36         "strings"
  37         "sync"
  38         "syscall"
  39         "time"
  40
  41         "go.cypherpunks.ru/recfile"
  42         "go.cypherpunks.ru/tai64n/v2"
  43         "golang.org/x/sys/unix"
  44 )
  45
  46 const (
  47         EnvDepFd        = "REDO_DEP_FD"
  48         EnvDirPrefix    = "REDO_DIRPREFIX"
  49         EnvDepCwd       = "REDO_DEP_CWD"
  50         EnvBuildUUID    = "REDO_BUILD_UUID"
  51         EnvStderrPrefix = "REDO_STDERR_PREFIX"
  52         EnvTrace        = "REDO_TRACE"
  53         EnvStderrKeep   = "REDO_LOGS"
  54         EnvStderrSilent = "REDO_SILENT"
  55         EnvNoSync       = "REDO_NO_SYNC"
  56         EnvStopIfMod    = "REDO_STOP_IF_MODIFIED"
  57
  58         RedoDir      = ".redo"
  59         LockSuffix   = ".lock"
  60         DepSuffix    = ".dep"
  61         TmpPrefix    = ".redo."
  62         LogSuffix    = ".log"
  63         LogRecSuffix = ".log-rec"
  64 )
  65
  66 var (
  67         NoSync       = false
  68         StderrKeep   = false
  69         StderrSilent = false
  70         StderrPrefix string
  71         StopIfMod    = false
  72         Jobs         sync.WaitGroup
  73
  74         flagTrace          *bool
  75         flagTraceAll       *bool
  76         flagStderrKeep     *bool
  77         flagStderrSilent   *bool
  78         flagForcedIfchange *bool
  79
  80         TracedAll bool
  81
  82         RunningProcs  = map[int]*os.Process{}
  83         RunningProcsM sync.Mutex
  84
  85         Err1WasTouched = errors.New("$1 was explicitly touched")
  86 )
  87
  88 func init() {
  89         cmdName := CmdName()
  90         if !(cmdName == CmdNameRedo || cmdName == CmdNameRedoIfchange) {
  91                 return
  92         }
  93         flagTrace = flag.Bool("x", false, "trace (sh -x) current targets")
  94         flagTraceAll = flag.Bool("xx", false,
  95                 fmt.Sprintf("trace (sh -x) all targets (%s=1)", EnvTrace))
  96         flagStderrKeep = flag.Bool("k", false,
  97                 fmt.Sprintf("keep job's stderr (%s=1)", EnvStderrKeep))
  98         flagStderrSilent = flag.Bool("s", false,
  99                 fmt.Sprintf("silent, do not print job's stderr (%s=1)", EnvStderrSilent))
 100         flagForcedIfchange = flag.Bool("f", false, "forced redo-ifchange")
 101 }
 102
 103 type RunError struct {
 104         Tgt      *Tgt
 105         DoFile   string
 106         Started  *time.Time
 107         Finished *time.Time
 108         Err      error
 109 }
 110
 111 func (e *RunError) Name() string {
 112         var name string
 113         if e.DoFile == "" {
 114                 name = e.Tgt.rel
 115         } else {
 116                 name = fmt.Sprintf("%s (%s)", e.Tgt, e.DoFile)
 117         }
 118         if e.Finished == nil {
 119                 return name
 120         }
 121         return fmt.Sprintf("%s (%.3fs)", name, e.Finished.Sub(*e.Started).Seconds())
 122 }
 123
 124 func (e RunError) Error() string {
 125         return fmt.Sprintf("%s: %s", e.Name(), e.Err)
 126 }
 127
 128 func mkdirs(pth string) error {
 129         if FileExists(pth) {
 130                 return nil
 131         }
 132         return os.MkdirAll(pth, os.FileMode(0777))
 133 }
 134
 135 func isModified(dep *Dep, tgt *Tgt) (
 136         modified bool, ourInode *Inode, hshPrev Hash, err error,
 137 ) {
 138         if dep == nil {
 139                 return
 140         }
 141         for _, ifchange := range dep.ifchanges {
 142                 if ifchange.tgt.a != tgt.a {
 143                         continue
 144                 }
 145                 ourInode, err = inodeFromFileByPath(tgt.a)
 146                 if err != nil {
 147                         if os.IsNotExist(err) {
 148                                 err = nil
 149                                 return
 150                         }
 151                         err = ErrLine(err)
 152                         return
 153                 }
 154                 hshPrev = ifchange.Hash()
 155                 modified = !ourInode.Equals(ifchange.Inode())
 156                 break
 157         }
 158         return
 159 }
 160
 161 func syncDir(dir string) error {
 162         fd, err := os.Open(dir)
 163         if err != nil {
 164                 return err
 165         }
 166         err = fd.Sync()
 167         fd.Close()
 168         return err
 169 }
 170
 171 func runScript(tgt *Tgt, errs chan error, forced, traced bool) error {
 172         tgtH, tgtT := pathSplit(tgt.a)
 173         redoDir := path.Join(tgtH, RedoDir)
 174         if err := mkdirs(redoDir); err != nil {
 175                 return TgtError{tgt, ErrLine(err)}
 176         }
 177
 178         shCtx := fmt.Sprintf("sh: %s: cwd:%s", tgt, tgtH)
 179         jsToken := jsAcquire(shCtx)
 180         jsNeedsRelease := true
 181         defer func() {
 182                 if jsNeedsRelease {
 183                         jsRelease(shCtx, jsToken)
 184                 }
 185         }()
 186
 187         // Acquire lock
 188         fdLock, err := os.OpenFile(
 189                 path.Join(redoDir, tgtT+LockSuffix),
 190                 os.O_WRONLY|os.O_TRUNC|os.O_CREATE,
 191                 os.FileMode(0666),
 192         )
 193         if err != nil {
 194                 return TgtError{tgt, ErrLine(err)}
 195         }
 196         flock := unix.Flock_t{
 197                 Type:   unix.F_WRLCK,
 198                 Whence: io.SeekStart,
 199         }
 200         lockRelease := func() {
 201                 tracef(CLock, "LOCK_UN: %s", fdLock.Name())
 202                 flock.Type = unix.F_UNLCK
 203                 if err := unix.FcntlFlock(fdLock.Fd(), unix.F_SETLK, &flock); err != nil {
 204                         log.Fatalln(err, fdLock.Name())
 205                 }
 206                 fdLock.Close()
 207         }
 208         tracef(CLock, "LOCK_NB: %s", fdLock.Name())
 209
 210         // Waiting for job completion, already taken by someone else
 211         if err = unix.FcntlFlock(fdLock.Fd(), unix.F_SETLK, &flock); err != nil {
 212                 if uintptr(err.(syscall.Errno)) != uintptr(unix.EAGAIN) {
 213                         fdLock.Close()
 214                         return TgtError{tgt, ErrLine(err)}
 215                 }
 216                 Jobs.Add(1)
 217                 if err = unix.FcntlFlock(fdLock.Fd(), unix.F_GETLK, &flock); err != nil {
 218                         log.Fatalln(err, fdLock.Name())
 219                 }
 220                 tracef(CDebug, "waiting: %s (pid=%d)", tgt, flock.Pid)
 221                 if FdStatus != nil {
 222                         if _, err = FdStatus.Write([]byte{StatusWait}); err != nil {
 223                                 log.Fatal(err)
 224                         }
 225                 }
 226                 go func() {
 227                         defer Jobs.Done()
 228                         tracef(CLock, "LOCK_EX: %s", fdLock.Name())
 229                 LockAgain:
 230                         if err := unix.FcntlFlock(fdLock.Fd(), unix.F_SETLKW, &flock); err != nil {
 231                                 if errors.Is(err, unix.EDEADLK) {
 232                                         time.Sleep(10 * time.Millisecond)
 233                                         goto LockAgain
 234                                 }
 235                                 log.Fatalln(err, fdLock.Name())
 236                         }
 237                         lockRelease()
 238                         tracef(CDebug, "waiting done: %s", tgt)
 239                         if FdStatus != nil {
 240                                 if _, err = FdStatus.Write([]byte{StatusWaited}); err != nil {
 241                                         log.Fatal(err)
 242                                 }
 243                         }
 244                         build, err := depBuildRead(tgt.dep)
 245                         if err == nil {
 246                                 if build != BuildUUID {
 247                                         err = errors.New("was not built: build differs")
 248                                 }
 249                         } else {
 250                                 if errors.Is(err, fs.ErrNotExist) {
 251                                         err = errors.New("was not built: no .dep")
 252                                 }
 253                         }
 254                         if err != nil {
 255                                 err = TgtError{tgt, err}
 256                         }
 257                         errs <- err
 258                 }()
 259                 return nil
 260         }
 261
 262         // It scans the whole .dep file while searching for the single target,
 263         // but that one is always located at the very end
 264         dep, err := depRead(tgt)
 265         if err != nil {
 266                 if errors.Is(err, fs.ErrNotExist) {
 267                         err = nil
 268                 } else {
 269                         lockRelease()
 270                         return TgtError{tgt, ErrLine(err)}
 271                 }
 272         }
 273
 274         // Check if it was already built in parallel
 275         if !forced && dep != nil && dep.build == BuildUUID {
 276                 lockRelease()
 277                 errs <- nil
 278                 return nil
 279         }
 280
 281         // Check if target is not modified externally
 282         modified, inodePrev, hshPrev, err := isModified(dep, tgt)
 283         if err != nil {
 284                 lockRelease()
 285                 return TgtError{tgt, ErrLine(err)}
 286         }
 287         if modified {
 288                 lockRelease()
 289                 if StopIfMod {
 290                         return fmt.Errorf("%s externally modified", tgt)
 291                 }
 292                 tracef(CWarn, "%s externally modified: not redoing", tgt)
 293                 go func() {
 294                         errs <- nil
 295                 }()
 296                 return nil
 297         }
 298         dep = nil
 299
 300         // Start preparing .dep
 301         fdDep, err := tempfile(redoDir, tgtT+DepSuffix)
 302         if err != nil {
 303                 lockRelease()
 304                 return TgtError{tgt, ErrLine(err)}
 305         }
 306         fdDepOpened := true
 307         fdDepExists := true
 308         fdDepW := bufio.NewWriter(fdDep)
 309         cleanup := func() {
 310                 lockRelease()
 311                 if fdDepOpened {
 312                         fdDep.Close()
 313                 }
 314                 if fdDepExists {
 315                         os.Remove(fdDep.Name())
 316                 }
 317         }
 318         if err = depBuildWrite(fdDepW, BuildUUID); err != nil {
 319                 cleanup()
 320                 return TgtError{tgt, ErrLine(err)}
 321         }
 322
 323         var cwd string
 324         var dirPrefix string
 325         var doFile *Tgt
 326         var doFileT string
 327         basename := tgtT
 328         runErr := RunError{Tgt: tgt}
 329         // Determine basename and DIRPREFIX
 330         {
 331                 doFileRelPath, upLevels, err := findDo(fdDepW, fdDep.Name(), tgtH, tgtT)
 332                 if err != nil {
 333                         cleanup()
 334                         return TgtError{tgt, ErrLine(err)}
 335                 }
 336                 if doFileRelPath == "" {
 337                         cleanup()
 338                         return TgtError{tgt, errors.New("no .do found")}
 339                 }
 340                 ents := strings.Split(tgtH, "/")
 341                 ents = ents[len(ents)-upLevels:]
 342                 dirPrefix = path.Join(ents...)
 343                 ups := make([]string, 0, upLevels+2)
 344                 ups = append(ups, tgtH)
 345                 for i := 0; i < upLevels; i++ {
 346                         ups = append(ups, "..")
 347                 }
 348                 ups = append(ups, doFileRelPath)
 349                 cwd = path.Clean(path.Join(ups[:len(ups)-1]...))
 350                 doFile = NewTgt(path.Join(ups...))
 351                 doFileT = path.Base(doFile.a)
 352                 if strings.HasPrefix(doFileT, "default.") {
 353                         basename = basename[:len(basename)-(len(doFileT)-len("default.")-len(".do"))-1]
 354                         runErr.DoFile = doFile.rel
 355                 }
 356         }
 357
 358         if err = depWrite(fdDepW, fdDep.Name(), tgtH, doFile, ""); err != nil {
 359                 cleanup()
 360                 return TgtError{tgt, ErrLine(err)}
 361         }
 362         if err = fdDepW.Flush(); err != nil {
 363                 cleanup()
 364                 return TgtError{tgt, ErrLine(err)}
 365         }
 366         fdDep.Close()
 367         fdDepOpened = false
 368         tracef(CWait, "%s", runErr.Name())
 369
 370         // Prepare command line
 371         var cmdName string
 372         var args []string
 373         if err = unix.Access(doFile.rel, unix.X_OK); err == nil {
 374                 cmdName = doFile.a
 375                 args = make([]string, 0, 3)
 376         } else {
 377                 cmdName = "/bin/sh"
 378                 if traced || TracedAll {
 379                         args = append(args, "-ex")
 380                 } else {
 381                         args = append(args, "-e")
 382                 }
 383                 args = append(args, doFileT)
 384         }
 385
 386         // Temporary file for stdout
 387         fdStdout, err := tempfile(tgtH, tgtT)
 388         if err != nil {
 389                 cleanup()
 390                 return TgtError{tgt, ErrLine(err)}
 391         }
 392         fdStdout.Close()
 393         tmpPath := fdStdout.Name() + ".3" // and for $3
 394         tmpPathRel := mustRel(cwd, tmpPath)
 395         args = append(
 396                 args,
 397                 path.Join(dirPrefix, tgtT),
 398                 path.Join(dirPrefix, basename),
 399                 tmpPathRel,
 400         )
 401         shCtx = fmt.Sprintf(
 402                 "sh: %s: %s %s cwd:%s dirprefix:%s",
 403                 tgt, cmdName, args, cwd, dirPrefix,
 404         )
 405
 406         cmd := exec.Command(cmdName, args...)
 407         cmd.Dir = cwd
 408         // cmd.Stdin reads from /dev/null by default
 409         cmd.Env = append(os.Environ(), fmt.Sprintf("%s=%d", EnvLevel, Level+1))
 410         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", EnvDirPrefix, dirPrefix))
 411         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", EnvBuildUUID, BuildUUID))
 412
 413         childStderrPrefixRaw := make([]byte, 8)
 414         if _, err = io.ReadFull(rand.Reader, childStderrPrefixRaw); err != nil {
 415                 panic(err)
 416         }
 417         childStderrPrefix := hex.EncodeToString(childStderrPrefixRaw)
 418         cmd.Env = append(cmd.Env, fmt.Sprintf(
 419                 "%s=%s", EnvStderrPrefix, childStderrPrefix,
 420         ))
 421
 422         fdNum := 0
 423         cmd.ExtraFiles = append(cmd.ExtraFiles, FdOODTgts)
 424         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvOODTgtsFd, 3+fdNum))
 425         fdNum++
 426         cmd.ExtraFiles = append(cmd.ExtraFiles, FdOODTgtsLock)
 427         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvOODTgtsLockFd, 3+fdNum))
 428         fdNum++
 429
 430         if FdStatus == nil {
 431                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=NO", EnvStatusFd))
 432         } else {
 433                 cmd.ExtraFiles = append(cmd.ExtraFiles, FdStatus)
 434                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvStatusFd, 3+fdNum))
 435                 fdNum++
 436         }
 437
 438         // Preparing stderr
 439         var fdStderr *os.File
 440         if StderrKeep {
 441                 fdStderr, err = os.OpenFile(
 442                         path.Join(redoDir, tgtT+LogSuffix),
 443                         os.O_WRONLY|os.O_CREATE|os.O_TRUNC,
 444                         os.FileMode(0666),
 445                 )
 446                 if err != nil {
 447                         cleanup()
 448                         return TgtError{tgt, ErrLine(err)}
 449                 }
 450         }
 451         tracef(CDebug, "%s", shCtx)
 452
 453         jsNeedsRelease = false
 454         Jobs.Add(1)
 455         go func() {
 456                 if JSR == nil {
 457                         // infinite jobs
 458                         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=NO", EnvJobs))
 459                 } else {
 460                         cmd.ExtraFiles = append(cmd.ExtraFiles, JSR)
 461                         cmd.ExtraFiles = append(cmd.ExtraFiles, JSW)
 462                         makeFlags := fmt.Sprintf(
 463                                 "%s %s%d,%d", MakeFlags, MakeJSArg, 3+fdNum+0, 3+fdNum+1,
 464                         )
 465                         makeFlags = strings.Trim(makeFlags, " ")
 466                         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", MakeFlagsName, makeFlags))
 467                         fdNum += 2
 468                         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvJSToken, jsToken))
 469                 }
 470
 471                 if FdStatus != nil {
 472                         if _, err = FdStatus.Write([]byte{StatusRun}); err != nil {
 473                                 log.Fatal(err)
 474                         }
 475                 }
 476
 477                 defer jsRelease(shCtx, jsToken)
 478
 479                 var finished time.Time
 480                 var exitErr *exec.ExitError
 481                 started := time.Now()
 482                 runErr.Started = &started
 483                 fdStdout, err = os.OpenFile(fdStdout.Name(), os.O_RDWR, os.FileMode(0666))
 484                 if err != nil {
 485                         if fdStderr != nil {
 486                                 fdStderr.Close()
 487                         }
 488                         runErr.Err = err
 489                         errs <- runErr
 490                         return
 491                 }
 492                 cmd.Stdout = fdStdout
 493                 fdDep, err = os.OpenFile(fdDep.Name(), os.O_WRONLY|os.O_APPEND, os.FileMode(0666))
 494                 if err != nil {
 495                         if fdStderr != nil {
 496                                 fdStderr.Close()
 497                         }
 498                         fdStdout.Close()
 499                         runErr.Err = err
 500                         errs <- runErr
 501                         return
 502                 }
 503                 fdDepOpened = true
 504                 fdDepW.Reset(fdDep)
 505                 cmd.ExtraFiles = append(cmd.ExtraFiles, fdDep)
 506                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvDepFd, 3+fdNum))
 507                 fdNum++
 508                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", EnvDepCwd, cwd))
 509
 510                 defer func() {
 511                         if fdDepOpened {
 512                                 fdDep.Close()
 513                         }
 514                         fdStdout.Close()
 515                         if fdStderr != nil {
 516                                 fdStderr.Close()
 517                                 logRecPath := path.Join(redoDir, tgtT+LogRecSuffix)
 518                                 if fdStderr, err = os.OpenFile(
 519                                         logRecPath,
 520                                         os.O_WRONLY|os.O_CREATE|os.O_TRUNC,
 521                                         os.FileMode(0666),
 522                                 ); err == nil {
 523                                         fields := []recfile.Field{
 524                                                 {Name: "Build", Value: BuildUUID.String()},
 525                                                 {Name: "PPID", Value: strconv.Itoa(os.Getpid())},
 526                                                 {Name: "Cwd", Value: cwd},
 527                                         }
 528                                         if cmd.Process != nil {
 529                                                 fields = append(fields, recfile.Field{
 530                                                         Name: "PID", Value: strconv.Itoa(cmd.Process.Pid),
 531                                                 })
 532                                         }
 533                                         ts := new(tai64n.TAI64N)
 534                                         ts.FromTime(started)
 535                                         fields = append(fields,
 536                                                 recfile.Field{Name: "Started", Value: tai64n.Encode(ts[:])},
 537                                         )
 538                                         ts.FromTime(finished)
 539                                         fields = append(fields,
 540                                                 recfile.Field{Name: "Finished", Value: tai64n.Encode(ts[:])})
 541                                         fields = append(fields, recfile.Field{
 542                                                 Name:  "Duration",
 543                                                 Value: strconv.FormatInt(finished.Sub(started).Nanoseconds(), 10),
 544                                         })
 545                                         fields = append(fields, recfile.Field{Name: "Cmd", Value: cmdName})
 546                                         for _, arg := range args {
 547                                                 fields = append(fields, recfile.Field{Name: "Arg", Value: arg})
 548                                         }
 549                                         for _, env := range cmd.Env {
 550                                                 fields = append(fields, recfile.Field{Name: "Env", Value: env})
 551                                         }
 552                                         if exitErr != nil {
 553                                                 fields = append(fields, recfile.Field{
 554                                                         Name:  "ExitCode",
 555                                                         Value: strconv.Itoa(exitErr.ProcessState.ExitCode()),
 556                                                 })
 557                                         }
 558
 559                                         w := bufio.NewWriter(fdStderr)
 560                                         {
 561                                                 var ifchanges []string
 562                                                 ifchanges, err = depReadOnlyIfchanges(tgt.dep)
 563                                                 if err != nil {
 564                                                         err = ErrLine(err)
 565                                                         goto Err
 566                                                 }
 567                                                 for _, ifchange := range ifchanges {
 568                                                         fields = append(fields, recfile.Field{
 569                                                                 Name:  "Ifchange",
 570                                                                 Value: ifchange,
 571                                                         })
 572                                                 }
 573                                         }
 574                                         _, err = recfile.NewWriter(w).WriteFields(fields...)
 575                                         if err != nil {
 576                                                 err = ErrLine(err)
 577                                                 goto Err
 578                                         }
 579                                         err = ErrLine(w.Flush())
 580                                 Err:
 581                                         if err != nil {
 582                                                 log.Print(err)
 583                                                 os.Remove(logRecPath)
 584                                         }
 585                                         fdStderr.Close()
 586                                 } else {
 587                                         log.Println("can not open", logRecPath, ":", err)
 588                                 }
 589                         }
 590                         lockRelease()
 591                         if fdDepExists {
 592                                 os.Remove(fdDep.Name())
 593                         }
 594                         os.Remove(fdStdout.Name())
 595                         os.Remove(tmpPath)
 596                         if FdStatus != nil {
 597                                 if _, err = FdStatus.Write([]byte{StatusDone}); err != nil {
 598                                         log.Fatal(err)
 599                                 }
 600                         }
 601                         Jobs.Done()
 602                 }()
 603                 stderr, err := cmd.StderrPipe()
 604                 if err != nil {
 605                         runErr.Err = err
 606                         errs <- runErr
 607                         return
 608                 }
 609                 started = time.Now()
 610                 err = cmd.Start()
 611                 if err != nil {
 612                         runErr.Err = err
 613                         errs <- runErr
 614                         return
 615                 }
 616                 RunningProcsM.Lock()
 617                 RunningProcs[cmd.Process.Pid] = cmd.Process
 618                 RunningProcsM.Unlock()
 619                 pid := fmt.Sprintf("[%d]", cmd.Process.Pid)
 620                 tracef(CDebug, "%s runs %s", tgt, pid)
 621
 622                 stderrTerm := make(chan struct{})
 623                 go func() {
 624                         scanner := bufio.NewScanner(stderr)
 625                         var line string
 626                         ts := new(tai64n.TAI64N)
 627                         for scanner.Scan() {
 628                                 line = scanner.Text()
 629                                 if strings.HasPrefix(line, childStderrPrefix) {
 630                                         line = line[len(childStderrPrefix):]
 631                                         if StderrPrefix == "" {
 632                                                 withPrependedTgt(line)
 633                                         } else {
 634                                                 stderrWrite(StderrPrefix + line + "\n")
 635                                         }
 636                                         continue
 637                                 }
 638                                 if fdStderr != nil {
 639                                         ts.FromTime(time.Now())
 640                                         fmt.Fprintln(fdStderr, tai64n.Encode(ts[:]), line)
 641                                 }
 642                                 if StderrSilent {
 643                                         continue
 644                                 }
 645                                 if MyPID != 0 {
 646                                         line = pid + " " + line
 647                                 }
 648                                 if StderrPrefix == "" {
 649                                         withPrependedTgt("[" + tgt.rel + "]" + line)
 650                                 } else {
 651                                         stderrWrite(StderrPrefix + "[" + tgt.rel + "]" + line + "\n")
 652                                 }
 653                         }
 654                         close(stderrTerm)
 655                 }()
 656
 657                 // Wait for job completion
 658                 <-stderrTerm
 659                 err = cmd.Wait()
 660                 RunningProcsM.Lock()
 661                 delete(RunningProcs, cmd.Process.Pid)
 662                 RunningProcsM.Unlock()
 663                 finished = time.Now()
 664                 runErr.Finished = &finished
 665                 if err != nil {
 666                         exitErr = err.(*exec.ExitError)
 667                         runErr.Err = err
 668                         errs <- runErr
 669                         return
 670                 }
 671
 672                 // Was $1 touched?
 673                 if inode, err := inodeFromFileByPath(tgt.a); err == nil {
 674                         if inodePrev == nil {
 675                                 runErr.Err = Err1WasTouched
 676                                 errs <- runErr
 677                                 return
 678                         }
 679                         if !inode.Equals(inodePrev) {
 680                                 runErr.Err = Err1WasTouched
 681                                 errs <- runErr
 682                                 return
 683                         }
 684                 }
 685
 686                 // Does it produce both stdout and tmp?
 687                 fiStdout, err := os.Stat(fdStdout.Name())
 688                 if err != nil {
 689                         runErr.Err = ErrLine(err)
 690                         errs <- runErr
 691                         return
 692                 }
 693                 tmpExists := false
 694                 _, err = os.Stat(tmpPath)
 695                 if err == nil {
 696                         if fiStdout.Size() > 0 {
 697                                 runErr.Err = errors.New("created both tmp and stdout")
 698                                 errs <- runErr
 699                                 return
 700                         }
 701                         tmpExists = true
 702                 } else if !errors.Is(err, fs.ErrNotExist) {
 703                         runErr.Err = ErrLine(err)
 704                         errs <- runErr
 705                         return
 706                 }
 707
 708                 // Determine what file we must process at last
 709                 var fd *os.File
 710                 var chmod fs.FileMode
 711                 if tmpExists {
 712                         fd, err = os.Open(tmpPath)
 713                         if err != nil {
 714                                 err = ErrLine(err)
 715                                 goto Finish
 716                         }
 717                         defer fd.Close()
 718                         if fi, rerr := fd.Stat(); rerr == nil {
 719                                 chmod = fi.Mode()
 720                         } else {
 721                                 err = ErrLine(rerr)
 722                                 goto Finish
 723                         }
 724                 } else if fiStdout.Size() > 0 {
 725                         fd = fdStdout
 726                 }
 727
 728                 // Do we need to ifcreate it, or ifchange with renaming?
 729                 if fd == nil {
 730                         os.Remove(tgt.a)
 731                         err = ifcreate(fdDepW, fdDep.Name(), tgtT)
 732                         if err != nil {
 733                                 err = ErrLine(err)
 734                                 goto Finish
 735                         }
 736                 } else {
 737                         var hsh Hash
 738                         if hshPrev != "" {
 739                                 _, err = fd.Seek(0, io.SeekStart)
 740                                 if err != nil {
 741                                         err = ErrLine(err)
 742                                         goto Finish
 743                                 }
 744                                 hsh, err = fileHash(fd)
 745                                 if err != nil {
 746                                         err = ErrLine(err)
 747                                         goto Finish
 748                                 }
 749                                 if hsh == hshPrev {
 750                                         tracef(CDebug, "%s has same hash, not renaming", tgt)
 751                                         err = ErrLine(os.Remove(fd.Name()))
 752                                         if err != nil {
 753                                                 goto Finish
 754                                         }
 755                                         if chmod != 0 {
 756                                                 err = ErrLine(os.Chmod(tgt.a, chmod))
 757                                                 if err != nil {
 758                                                         goto Finish
 759                                                 }
 760                                         }
 761                                         err = ErrLine(os.Chtimes(tgt.a, finished, finished))
 762                                         if err != nil {
 763                                                 goto Finish
 764                                         }
 765                                         if !NoSync {
 766                                                 err = ErrLine(syncDir(tgtH))
 767                                                 if err != nil {
 768                                                         goto Finish
 769                                                 }
 770                                         }
 771                                         err = ErrLine(depWrite(fdDepW, fdDep.Name(), tgtH, tgt, hsh))
 772                                         if err != nil {
 773                                                 goto Finish
 774                                         }
 775                                         goto RecCommit
 776                                 }
 777                         }
 778                         if !NoSync {
 779                                 err = ErrLine(fd.Sync())
 780                                 if err != nil {
 781                                         goto Finish
 782                                 }
 783                         }
 784                         err = ErrLine(os.Rename(fd.Name(), tgt.a))
 785                         if err != nil {
 786                                 goto Finish
 787                         }
 788                         if !NoSync {
 789                                 err = ErrLine(syncDir(tgtH))
 790                                 if err != nil {
 791                                         goto Finish
 792                                 }
 793                         }
 794                         err = ErrLine(depWrite(fdDepW, fdDep.Name(), tgtH, tgt, hsh))
 795                         if err != nil {
 796                                 goto Finish
 797                         }
 798                 }
 799
 800         RecCommit:
 801                 // Commit .dep
 802                 err = ErrLine(fdDepW.Flush())
 803                 if err != nil {
 804                         goto Finish
 805                 }
 806                 if !NoSync {
 807                         err = ErrLine(fdDep.Sync())
 808                         if err != nil {
 809                                 goto Finish
 810                         }
 811                 }
 812                 err = ErrLine(os.Rename(fdDep.Name(), tgt.dep))
 813                 if err != nil {
 814                         goto Finish
 815                 }
 816                 fdDepExists = false
 817                 if !NoSync {
 818                         err = ErrLine(syncDir(redoDir))
 819                         if err != nil {
 820                                 goto Finish
 821                         }
 822                 }
 823                 fdDep.Close()
 824                 fdDepOpened = false
 825
 826                 // Post-commit .dep sanitizing
 827                 dep, err = depRead(tgt)
 828                 if err == nil {
 829                         ifchangeSeen := make(map[string]struct{}, len(dep.ifchanges))
 830                         for _, ifchange := range dep.ifchanges {
 831                                 ifchangeSeen[ifchange.tgt.a] = struct{}{}
 832                         }
 833                         for _, ifcreate := range dep.ifcreates {
 834                                 if _, exists := ifchangeSeen[ifcreate.a]; exists {
 835                                         tracef(CWarn, "simultaneous ifcreate and ifchange records: %s", tgt)
 836                                 }
 837                         }
 838                 } else if errors.Is(err, fs.ErrNotExist) {
 839                         err = nil
 840                 } else {
 841                         err = ErrLine(err)
 842                         goto Finish
 843                 }
 844
 845         Finish:
 846                 runErr.Err = err
 847                 errs <- runErr
 848         }()
 849         return nil
 850 }
 851
 852 func isOkRun(err error) bool {
 853         if err == nil {
 854                 return true
 855         }
 856         var runErr RunError
 857         if errors.As(err, &runErr) && runErr.Err == nil {
 858                 tracef(CRedo, "%s", runErr.Name())
 859                 return true
 860         }
 861         tracef(CErr, "%s", err)
 862         return false
 863 }